About 3,500 people are killed on the UK roads every year. That's the equivalent of about 10 plane-loads of passengers - the number said to have been recently targeted by terrorists - year after year. It is death on a massive scale, and I'm sure any day now John Reid will intervene.

The Home Secretary will say that extraordinary measures are necessary to keep Britons safe - and that considerable disruption must be accepted as the price. There will be great costs, both in financial terms and in inconvenience, and even a loss of what you might call freedom; but John Reid will ask the people of Britain to understand and to do their part.

Then he'll cut the nationwide speed limit to 15mph, and announce the phasing in of compulsory speed governors on all vehicles. Instantly, 3,500 lives a year will be saved. "It will be tough, but worth it," he'll say. "I'm sure no one could question the need to save all those precious lives."

Now, I'm a cyclist who rarely drives, and would be delighted from a personal perspective were this measure to be implemented. I'm not advocating it, though, even though our country does needs tougher road-safety measures, and even though a 15mph speed limit would certainly be more rational than the massive disruption we've seen - and continue to see - at the nation's airports.

Once it was the function of the public - the mob, even - to engage in hysterical panic. Increasingly, it seems, this is a function that is being nationalised and bureaucratised. "Terrorism" is the bogey-man of the day (the dangers of the roads are a long, long way down the list), so every conceivable countermeasure is thrown at it, to the point of bringing the country to a near-halt and abolishing the civil liberties for which we are supposed to be fighting.

The question of whether this is a proportionate response to the threat, or a rational use of resources, will be ignored. Reacting in a restrained, balanced way would be a tougher, braver thing for our politicians to do. Someone might still have managed to bomb a plane - as they might any day, no matter what measures are taken. But the risk would be tiny - the statistical risk of driving to the airport still far greater.

And if you create confusion and chaos, as the government measures did, then while you might have blocked up one angle of attack, you open others, as shown by the fact that a 12-year-old was still able to get on a plane without a ticket or travel documents, and a man still able to get on an unguarded empty plane.

And what about those long snaking airport queues - wouldn't they have been an incredibly easy soft target? And the trains, the London Tube, a crowded concert ... were members of a conspiracy that escaped a dragnet to be determined to use any weapons they had at their disposal, then there would be no way of stopping them.

The government action is doing nothing to make us safer. All it is doing is shouting: "Look, we are doing something! Look at this terrible threat! Panic! Panic!" As a letter writer to the Guardian commented, what we were treated to was security theatre. And what an expensive act of absurdity it was.